The present invention relates to a small-sized and high-performance optical memory device suitable for use in a small-sized computer such as a portable computer. More particularly, the present invention relates to a small-sized optical memory device the access speed and data transfer rate of which are faster than those of the conventional magnetic memory.
File memories previously used for a small-sized portable computer such as a laptop computer include a fixed magnetic disk, a floppy disk, etc. However, these file memory devices present a great problem pertaining to the performance thereof. A first problem is concerned with the fact that the distance between the magnetic head and the recording medium is very small in the case of the magnetic memory. More particularly, when the magnetic memory device is used in a strongly vibrational condition as in a portable computer, the destruction of data may be caused by the recording medium touching the magnetic head or the like, thereby deteriorating the reliability. A second problem is that the demand for a increase in memory capacity will result in an increase in the size of the memory device and hence an increase in the size of the file apparatus. A third problem is that it is very difficult to significantly shorten the access time. This is because in the case of the magnetic memory the magnetic head must be mechanically moved by large strokes.